A percolating path to green iron

Cell Reports Physical Science, vol. 6, pp. 102729

Abstract

About 1.9 gigatons of steel is produced every year, emitting 8% (3.6 gigatons) of global CO 2 in the process. More than 50% of the CO 2 emissions come from a single step of steel production, known as ironmaking. Hydrogen-based direct reduction (HyDR) of iron oxide to iron has emerged as an emission-free ironmaking alternative. However, multiple physical and chemical phenomena ranging from nanometers to meters inside HyDR reactors alter the microstructure and pore networks in iron oxide pellets, in ways that resist gaseous transport of H 2 /H 2 O, slow reaction rates, and disrupt continuous reactor operation. Using synchrotron nano X-ray computed tomography and percolation theory, we quantify the evolution of pores in iron oxide pellets and demonstrate how nanoscale pore connectivity influences micro- and macroscale flow properties such as permeability, diffusivity, and tortuosity. Our modeling framework connects disparate scales and offers opportunities to accelerate HyDR.

Authors 9

1. Subhechchha Paul

   SLAC National Accelerator Laboratory · Stanford University

   Affiliation as printed

   Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA

   SLAC National Accelerator Laboratory, Stanford, CA 94025, USA

2. Brinthan Kanesalingam

   SLAC National Accelerator Laboratory · Stanford University

   Affiliation as printed

   Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA

   SLAC National Accelerator Laboratory, Stanford, CA 94025, USA

3. Yan Ma

   Max-Planck-Institut für Nachhaltige Materialien · Delft University of Technology

   Affiliation as printed

   Department of Materials Science and Engineering, Delft University of Technology, Delft 2628 CD, the Netherlands

   Max Planck Institute for Sustainable Materials, 40237 Düsseldorf, Germany

4. Julie Villanova

   European Synchrotron Radiation Facility

   Affiliation as printed

   European Synchrotron Radiation Facility (ESRF), 38043 Grenoble, France

5. Guillermo Carlos Requena Aachen Department of Metallic Structures and Materials Systems for Aerospace

   Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR) · RWTH Aachen University

   Affiliation as printed

   Department of Metallic Structures and Materials Systems for Aerospace, RWTH Aachen University, 52062 Aachen, Germany

   Institute for Frontier Materials on Earth and in Space, German Aerospace Center (DLR), 51147 Cologne, Germany

6. Stanley Chidubem Akpu

   Nnamdi Azikiwe University

   Affiliation as printed

   Department of Chemical Engineering, Nnamdi Azikiwe University, Awka 420007, Nigeria

7. Dierk Raabe

   Max-Planck-Institut für Nachhaltige Materialien

   Affiliation as printed

   Max Planck Institute for Sustainable Materials, 40237 Düsseldorf, Germany

8. Ilenia Battiato

   Stanford University

   Affiliation as printed

   Department of Energy Science and Engineering, Stanford University, Stanford, CA 94305, USA

9. Leora E. Dresselhaus‐Marais corresponding

   SLAC National Accelerator Laboratory · Stanford University

   Affiliation as printed

   Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA

   Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA

   SLAC National Accelerator Laboratory, Stanford, CA 94025, USA